false
Catalog
EP on EP Episode 63 - Proton Beam Ablation
EP on EP Episode 63_ Proton Beam Ablation
EP on EP Episode 63_ Proton Beam Ablation
Back to course
[Please upgrade your browser to play this video content]
Video Transcription
Hi, this is Eric Prostowski. Welcome to another segment of EP on EP. A buddy of mine for years, we go back many years, Dr. Douglas Packer, who is currently the John Nessif Professor of Medicine at the Mayo Clinic and Director of the Translational Laboratories. Doug, it's always a pleasure to have you back on the show. Thank you. It's good to be here, Eric. So, we've talked about so many other topics in the past. We've had this long journey with this particle therapy that I know about, but I think it's now come to the point that, you know, it's getting in the literature. Why don't you take us through what particle therapy is for ablation, maybe some of the early studies you did, and then we can move into where we're going to use it in patients. So Eric, if we go back seven or eight years, we were looking for an energy source. We've been doing radiofrequency, we've been doing laser, we've been doing all kinds of things with different targets and different intentions. We wanted to be successful in ablating from outside the body. No catheters, no nothing. And we found an energy source, protons and carbon. Now they're different because if you look at radiofrequency energy, it's kind of a sine wave. Okay. But if you look at protons and carbon beam, then it's a Bragg peak. So you have an energy that's delivered. You don't lose much of it as you're going through the body to your target, and then it immediately fires. It immediately delivers the energy. Let me stop you for just one moment because you've talked to me about this in the past, but I don't think it's generally known. Tell us what a Bragg peak is for those listening. A Bragg peak is just the way that atoms and protons and carbon gets delivered. In other words, it's not this sine wave. It's a stream of atoms that are going at the speed of light. They start to slow down and all of the energy is dumped in one place. Okay. I got it. It's pinpoint. It's pencil beam. It's one to two millimeters of precision in dumping that energy. And it doesn't keep going. So if you're aiming for the left ventricle scar, if you're aiming for a pulmonary vein, it's not going to keep going into the esophagus. I got it. So it goes right where you want it. Yeah. Okay. So no collateral damage, theoretically. Well, that's what we have to prove. Right. But that's the theory, right? And that's the work we've been doing over the last three or four years. All right. So let's talk about some of the work. I know you started in basic area with animal studies. Tell us about some of the animal studies. Most of the work we've done has been with animals. The reason why is there are some that have just launched into patients. This is different. Right. This is not easy. This is potentially problematic. And so we said that you really need to understand the basic science first. That's where we started. And that's where we've done most of our work. And so what we did is we said, number one, if you're going to know a blade VT, for example, you need to know your arrhythmias source. And you need to know it well. You can do that with a 12-lead ECG, with a 12-lead Holter, you can do it with ECGI. And then you need to know what your structural source is. A scar. Somebody's got ischemic VT and there's a scar. And so you're aiming for that scar. So now you know the electrophysiologic target and you know the structural target. And then what you do is a series of steps that probably won't mean much to everybody, but you do contouring. And so you kind of design a line around the structure that you're trying to hit. Now the heart's beating though. So how do you take care of that? So then what you have to do is you have to do simulations. And the simulation is taking into account heart motion. And then you have to do treatment planning. So how much energy are you going to deliver to one specific spot? So let's take one of your... I know one of your publications on the AV Note, where you targeted to get, I think, Hart Buck, if I remember that paper. And it was very successful. So when you actually deliver the energy, is it like a millisecond? I mean, is it that quick? I mean, what's the time of energy delivery? Well if you're delivering 30,000 carbon atoms, it takes a little bit longer than that. But it is on the order of parts of seconds, rather than a 30-second delivery with a catheter. Well, the reason I asked that was I was thinking of the view of the heart's moving, you know, so you have to get that in it where you want it to go to at just the right time and not too much time. So how does that work? So the way that works is it's called treatment planning. And so what you do is you look at the cardiac cycle. And as you're looking at the cardiac cycle, there's going to be different phases of the cardiac cycle. We usually talk about it as being 10 phases, or 16 phases, or 24 phases. And you deliver at one phase, say 70%. And then what you have to do is you have to accommodate changes that are going to occur elsewhere in different phases. So then you go to the next phase, and the next phase, and the next phase, and you find out where they match. So the 70% phase matches 80%, matches 90%, and you shoot for that. I gotcha. So having said that, that's one of the papers I've read and I was very impressed with it. Have you gone into man? We're doing a lot of photon in patients with VT. The big issue here is FDA, IDE, and so we're working on getting the FDA, IDE part of this taken care of so that we can actually do patients with photons, or with protons. All right, so let's look into the future. I know that just because you and I have talked about this over the years, this has been a long journey for you. This wasn't something that you did two years ago. You've been working on this for a long time. And you have to have a game plan, I'm sure, in your mind of what this looks like for the rest of us. In other words, are we going to have a console? Are we going to have ... You're going to map it up with an EGI type thing. What is your view of this as a commercial product? I know you're not quite there yet, but you must have thought of that. What do you want it to look like for us if we were going to use it? Do you have to have some special energy source at your site? I mean, what's going to ... Seriously, what is this going to look like? Well, you do. So what's Eric going to be doing two years from now is you identify where the electrophysiologic source is, and then you figure out where you're going to be shooting. And then you take a pot of atoms. That's your energy source. You put them through a synchrotron, and then you run them through a linear accelerator, and you speed them up to almost the speed of light. And then you fire them to a particular site. So you and I are going to have to be real good at identifying where these targets are going to be coming from. You and I are going to have to be real good at identifying what we're going to hit, how we're going to accommodate the change in heart rate over the course of these different phases. And we can do it. We can do it with photons now, and we can do it in animals with protons. And so what you're looking for is a photon or proton system. Now, it turns out that these things are relatively inexpensive. A photon system only costs $220 million. Oh, that's an easy one. I'd like to go to my administration and say, when can we put this into our next budget cycle? Right. So what we do is we work with radiation oncologists, and they're using it for cancer. And what we're doing is we're right now in the process of creating a system that would only be $30 million. Oh, so you're coming almost down to my lab budget. Yeah. Anyway. Yeah. So, but this is exciting work. I've really been watching this along over the years. I think it's extremely exciting, and you're to be congratulated for pushing it forward. And I know the way innovation goes, it'll get to a point where actually it will be affordable and usable in labs at some point. I mean, I know you're teasing with the $30 million, but it's clearly going to get to that point. It's just going to take a little more time. We get through the FDA IDE, and we're on our way. Douglas, great to hear from you again. Yeah, talk to you. Thank you very much. Sometime we're going to need to get together and go to Bullock's. It's a deal. Okay.
Video Summary
Dr. Douglas Packer, Director of Translational Laboratories at the Mayo Clinic, discusses particle therapy for ablation in a conversation with Eric Prostowski. Particle therapy uses protons and carbon beams to target specific areas in the body without causing collateral damage. The process involves contouring the structure, simulations to account for heart motion, and treatment planning to determine how much energy to deliver and at which phase of the cardiac cycle. Currently, the therapy is being used in animal studies and efforts are underway to obtain FDA approval for human trials. The hope is to eventually make particle therapy more affordable and accessible for clinical use.
Keywords
particle therapy
ablation
protons
carbon beams
targeted treatment
Heart Rhythm Society
1325 G Street NW, Suite 500
Washington, DC 20005
P: 202-464-3400 F: 202-464-3401
E: questions@heartrhythm365.org
© Heart Rhythm Society
Privacy Policy
|
Cookie Declaration
|
Linking Policy
|
Patient Education Disclaimer
|
State Nonprofit Disclosures
|
FAQ
×
Please select your language
1
English